Final answer:
Without a logical or common column to match on, you cannot perform an equijoin between the EMPLOYEES and SCHEDULES tables. A non-equijoin can be used if there's a logical condition for joining the tables;
Step-by-step explanation:
If the EMPLOYEES table and the SCHEDULES table do not share any corresponding columns (meaning there's no common column to match rows on), you typically would not be able to perform an equijoin (a join condition that compares columns for equality). However, it is not completely accurate to say that you cannot join these two tables at all. In SQL, a non-equijoin can sometimes be used to join two tables based on a condition that is not based on equality but instead on other operators like '<', '>', '<=', or '>='.
Using a non-equijoin could allow you to join the two tables on a logical or business-related condition if there is a relevant one. However, without a logical relationship or a join condition, a meaningful join cannot be performed. A full outer join is also an option, which returns all records when there is a match in either left or right table. This, however, generally requires some form of commonality or relationship between the two tables to be useful.
In summary, without additional context on how these tables might logically relate, it's not possible to provide a definitive answer. You would need to establish some form of a meaningful relationship between the two tables to determine the appropriate join.